Shoe bottom filling material



Patented Apr. 20, 1943 SHOE BOTTOM FILLING MATERIAL George E. Ehle, Lancaster Township, Lancaster County, Pa., assignor to Armstrong Cork Company, Lancaster, Pa., a corporation of Pennsylvania No Drawing. Application April 11, 1942, A

Serial No. 438,585

14 Claims.

This application is a continuation-in-part of my application, Serial No. 220,697, filed July 22, 1938, and relates to shoe bottom filling materials and, more particularly, to a shoe bottom filling material of the type commonly known as hot" shoe fillers which need the application of heat or heat and moisture to render them workable.

Such compositions generally comprise a comminuted body material, such as ground cork, and a thermoplastic binder. When it is desired to use the composition to fill shoe bottoms, a mass of the material is placed in a heating device, commonly known as a "shoe filler heater, and heated to render it plastic and spreadable. The temperature of the heater during such conditioning generally ranges between 215 F. and 218 F.

I have found in many instances that during the conditioning operation, with dry heat, the temperature of the mass rises slowly to perhaps 240 F. and thence quickly to a temperature of 300 F. or more. At such temperatures, the plastic mass quickly chars and becomes unsuitable for use.

This undesirable characteristic of hot shoe fillers has long been recognized in the shoe industry and many unsuccessful attempts have been made to overcome it. If moisture is injected, it must be subsequently evaporated from the shoe. The only other method provided heretofore to overcome such condition which meets with some degree of success has been to keep careful guard over the temperature of the heater and the interior temperature of the heated mass in order that the operator might shut off the heat when dangerous temperatures are reached. It will be appreciated such method is highly undesirable since it considerably increases the expense of the operation and entails loss of time in permitting the filler to cool to safe temperatures whereupon it must be reheated and the same procedure followed. Careless or inefficient operatorsunskilled labor is generally used in the operationmilitate against successfully following such method. The additional expense and waste of time involved in following such procedure while conditioning the filler for use is so great that the industry is gradually turning to the use of what are known as cold fillers which do not require heat conditioning but which are considerably more expensive than the hot fillers.

The chief object of this invention is to provide a hot shoe bottom filling material which not only possesses the usual physical attributes necessary and desirable for the purpose but which can "be conditioned in the usual manner without danger of charring. An object of my invention is to provide an economical and inexpensive hot shoe bottom filling material which contains an ingredient which inhibits or obviates charring during the conditioning operation with dry heat. A further object is to provide a shoe bottom filling material which can be conditioned with dry heat in the manner common to the industry without requiring additional time and expense to guard against combustion thereof.

My improved shoe bottom filling material comprises a comminuted body material substantially free from water, a plasticized resinous binder, and a material which inhibits charring or burn ing of the composition during the conditioning operation. The charring inhibitor may be chosen from a group consisting of oxalic acid, phosphoric acid, sulfuric acid, monochloracetic acid, and trlchloracetic acid. A satisfactory shoe bottom filling material maybe formed of the following ingredients in the proportions given by weight:

Parts Binder:

FF rosin -3695 Mineral oil 30.0

Oxalic acid v 0.5

Filler:.

20/30 cork granules 11.75

14/20 cork granules 11.75

The rosin and mineral oil are placed in a heated kettle and stirred together at 275 F. until a homogeneous mixture is obtained. At that time part of oxalic acid is added and thoroughly mixed with the rosin-oil mixture. The mixture is then cooled to approximately 250 F. for addition to the fillers. The required amount of cork granules are weighed and placed in a mixer. The binder is added thereto and quickly stirred therein and thoroughly coats each granule of cork with a thin film of binder without impregnation. After a satisfactory admixture is made, the material is removed from the mixer and formed into bricks or loaves of any suitable size and shape.

In place of rosin, I may use Manila gum or rosin ester or other similar synthetic or natural resin. The mineral oil is used primarily to plasticize the rosin and the type I prefer to use is that commonly known as Circo xxx Heavy, a very viscous mineral oil, although, if desired. othersgitable mineral or vegetable oils or paraflin waxes may be used. Other suitable and well known filler ingredients such as wood flour, com minuted fibrous materials or the like may be used instead of comminuted cork. Oxalic acid is used in the above composition preferably in an amount ranging from 0.5 to 1% of the binder by weight. It will be understood phosphoric acid, sulfuric acid, monochloracetic acid, and trichloracetic acid may replace oxalic acid in the above compound with satisfactory results; preferably, if monochloracetic acid or trichloracetic acid are substituted for oxalic acid, they are used in an amount about 1% of the binder by weight.

Ido not know definitely why the presence of these specific acids inhibits or obviates charring-their effect may be due to their acidic nature or their reducing action or to both. I have definitely ascertained by repeated experiments, however, that if to 1% phosphoric acid, sulfuric acid, oxalic acid, monochloracetic acid, or trichloracetic acidbe used with a resinous binder, such as rosin, charring of the composition at temperatures normally used during the conditioning operation is obviated,

A second satisfactory shoe filling material may comprise the following, all proportions being given by weight:

Parts by weight Binder:

' Bexin 70 Benny resin 30 Acid 1 Filler:

14/30 cork granules The acid in such compound is chosen from the group consisting of oxalic acid, phosphoric acid, sulfuric acid, monochloracetic acid, and trichloracetic acid. Benny" resin, of course, is a specific type of rosin available on the open market. Bexin is available as a commercial material; it is, I believe, the unsaponifled residue remaining after the causticizing of rosin to form a soap used for paper size. The ingredients may be compounded in the manner disclosed above to form the desired shoe filling material.

' A composition satisfactory for my purposes and similar to the above except that a siccative oilresin gel is added-to toughen and strengthen the binder, is formed as follows, all parts being by weight:

Parts Binder:

FF rosin 65 Siccative oil-resin gel 20 Mineral oil 14 Oxalic acid 1 Filler:

20/ cork granules 11.75 14/20 cork granules 11.75

By the term siccative oil I wish to include both drying and semi-drying oils, such as linseed, soya bean, China-wood and menhaden oils. It will be understood other drying or semi-drying oils or mixtures thereof may be used if desired.

The gel may be produced in any desired manner such for example as by heating or oxidizing; The oil may be mechanically oxidized in the presence of a resin in the usual heated beaters, such as the Bedford machine or it may be oxidized by the scrim process whereinthe oil is trickled over hanging sheets of scrim cloth in a heated chamber until a sufiiciently thick layer of gelled oil is obtained. The resin may be then incorporated with the oilgel so formed by the use of a suitably heated mixing kettle. I have found that a thoroughly oxidized oil-resin gel produced by mechanically oxidizing a mixture of 75 parts forms a satisfactory strengthening and toughenv ing agent for my binder.

This mechanically oxidized oil and rosin is discharged from the oxidizing kettle. and permitted to cool. The gel produced is relatively stiir, tough, flexible and coherent. The rosin and mineral oil are placed in a suitably heated mixing kettle and melted together at a temperature of approximately 275 F. The gel is cut into small pieces convenient for handling and added to the rosin-oil mixture at a temperature of 380-420 F. and melted into the mixture. The mixture is then cooled to 275 F. and the oxalic acid added R31? weight linseed oil and 25 parts by weight rosin and thoroughly stirred therein. The mixture is cooled to 250 F. for addition to the fillers. 1

The desired quantity of cork granules are placed in a mixer and the binder added thereto and quickly stirred therein and thoroughly coats each granule of cork with a thin film of binder without impregnation. After a satisfactory admixture is made the material is removed from the mixer and formed into bricks or loaves of any desired size and shape.

As described above, suitable equivalent ingreclients may be used in place of rosin, or mineral oil 'in the above composition. Other suitable fillers may, of course, be used in place of cork granules. In place of oxalic acid, I may use phosphoric acid, sulfuric acid, monochloracetic acid, or trichloracetic acid as discussed above. Other substances may be added to the binder to lend specific properties thereto, if desired, in order that it may be more or less resistant to the solvents commonly used in the shoe industry or for other purposes.

In use, a number of bricks or loaves of shoe and returns to its original condition. It will be appreciated my material may remain in the heating device for long periods of time without charring or requiring the device to be cooled to prevent such charring.

My invention permits hot shoe fillers to be conditioned with dry heat without charring and obviates the expense and time involved in carefully watching the temperature of the heater in which the material is conditioned or in evaporating extraneous moisture from shoes filled with a hot filler to which water has been added to inhibit charring. Mymaterial possesses the usual physical attributes necessary and desirable for the purpose of filling shoe bottoms. It is inexpensive to manufacture and economical in use, and does not require expensive machinery in its manufacture or use. Highly skilled labor is not required since it is not necessary to guard the interior of the mass against high temperatures arisingduring the conditioning operation.

While I have described certain preferred embodiments of my invention, it will be understood that the invention is not limited to the specific examples but may be otherwise embodied and practiced within the scope of the following claims.

I claim:

1. A shoe bottom filling material comprising a comminuted body material substantially free from water, rosin, a plasticizer therefor and a charming inhibitor in an amount sumcient to aaraeea furic acid, monochloracetic acid and trichloracetic acid.

2. A shoe bottom filling material comprising a comminuted body material substantially free from water, a binder therefor, and a charring inhibitor in an amount sufficient to inhibit charring during the conditioning operation, said inhibitor being selected from a class consisting oi oxalic acid, phosphoric acid, sulfuric acid, monochloracetic acid and trichloracetic acid, said binder containing rosin, a plasticizer thereof and a siccative oil-resin gel.

3. A shoe bottom filling material comprising cork granules substantially free from water,'a binder therefor, and a charring inhibitor in an amount suificient to inhibit charrlng during the conditioning operation and ranging from /2% to 1% of the binder, said inhibitor being selected from a class consisting of oxalic acid, phosphoric acid, sulfuric acid, monochloracetic acid and trichloracetic acid, said binder containing rosin, mineral oil, and a siccative oil-resin gel.

4. A shoe bottom filling material comprising a comminuted body material substantially free from water, a plasticized rosin binder, and a charring inhibitor in an amount sumcient to inhibit charring during the conditioning operation, said inhibitor being selected from a class consisting of oxalic acid, phosphoric acid, sulfuric acid, monochloracetic acid and I trichloracetic acid, said binder coating said comminuted body material without substantial impregnation.

5. A hot shoe bottom filling material having a plasticized rosin binder which will char upon prolonged dry heating at conditioning temperatures and containing suficient charringinhibltor to suficient to inhibit charring during the conditioning operation, said inhibitor being selected from a class consisting of oxalic acid, phosphoric acid, sulfuric acid, monochloracetic acid and trichloracetic acid.

8. A slice bottom filling material according to claim 7, in which the charring inhibitor is present in an amount ranging from to 1% of the binder.

a. A shoe bottom filling material comprising a comminuted body material, a binder therefor which will char upon prolonged dry heating at conditioning temperatures, and a charting inhibitor in an amount sufficient to inhibit charring during the conditioning operation, said inhibitor being selected from a class consisting of oxalic acid, phosphoric acid, sulfuric acid, monochloracetic acid and trlchloracetic acid, said binder containing a resinous material, a plasticizer therefor and a strengthening and toughening material.

10. A shoe bottom filling material according to claim 9, in which the strengthening and toughen" ing material comprises a siccative oil-resin gel.

11. A shoe bottom filling material comprising a comminuted body material which will char upon prolonged dry heating at conditioning temperatures, a binder therefor, and a char-ring inhibitor in an amount sufilcient to inhibit charring during the conditioning operation, said inhibitor being selected from a class consisting of oxalic acid, phosphoric acid, sulfuric acid, monochloracetic acid and trlchloracetic acid.

12. A shoe bottom filling material comprising a comminuted body material, a binder therefor which will char upon prolonged dry heating at inhibit charring during the conditioning operation, said inhibitor being selected from a class consisting of oxalic acid, phosphoric acid, sulfuric acid, monochloracetic acid and trichloracetic acid.

6. Shoe bottom filling material containing rosin and a charring inhibitor in amount sumcient to inhibit charring during the conditioning operation, said inhibitor being selected from a class consisting of oxalic acid, phosphoric acid, sulfuric acid, monochloracetic acid and trichloracetic acid. l

7. A shoe bottom filling material comprising comminuted body material substantially free from water which will char upon prolonged dry heating at conditioning temperatures, a resinous binder and a charring inhibitor in an amount conditioning temperatures containing a resinous material and a plasticizer, and a charring inhibitor in an amount sumcient to inhibit charrlng during the conditioning operation, said inhibitor being selected from a class consisting of oxalic acid, phosphoric acid, sulfuric acid, monochloracetic acid and trichloracetic acid.

13. A shoe bottom filling material comprising a comminuted body material, a binder therefor, and a charring inhibitor, said inhibitor being selected from a class consisting of oxalic acid, phosphoric acid, sulfuric acid, monochloracetic acid and trichloracetic acid.

14. A shoe bottom filling material according to claim 13, in which the binder includes a resin.

GEORGE E. EHLE. 

